Evidentiality and Source Monitoring in Turkish

This paper investigates the acquisition of evidentiality (the linguistic encoding of information source) and its relation to evidential reasoning in Turkish children. Previous studies suggest that evidential morphology is acquired relatively late, perhaps in accordance with developing cognitive abilities (Aksu-Koc, 1988 on Turkish). We focus on two evidential verbal morphemes in Turkish: -DI, used to indicate direct evidence, and -MIS, used to convey hearsay/indirect experience. We designed six experiments, three linguistic and three non-linguistic ones to find out whether Turkish children have acquired the semantics and pragmatics for these morphemes (Exp. 1-3) and understand the source concepts behind them (Exp. 4-6). Twenty children participated ranging between 3;5 and 5;3 years (mean: 4;1). In experiment 1, an elicited production task, children had to retell various events. If children had witnessed the event, they were expected to produce –DI; if they had been verbally informed or had inferred that the event had taken place, the hearsay morpheme –MIS was required. Children used –DI and –MIS interchangeably (proportion of correct responses 56% and 58% respectively, p=.70). Experiment 2 was a comprehension experiment conducted to see if children can attribute a sentence with an evidential morpheme to one of two speakers with appropriate access to information. In two conditions seeing vs. inferring and seeing vs. hearing were contrasted: children again failed to link each morpheme to the relevant information source (51% vs. 53% of correct responses for –DI and –MIS respectively, p=.79). Experiment 3 asked whether children trusted a character who used either the direct evidence morpheme or its full verb counterpart (“I saw that...”) more than a character who employed the hearsay morpheme or its full verb counterpart (“I heard that...”). Participants failed to appreciate the pragmatics of evidential morphology (success rate: 44.6%). Despite their poor linguistic performance, children showed reliably better understanding of source concepts in non-linguistic tasks. Experiment 4 showed they were able to report their own sources of information about an event (63%, 67% and 42% of correct responses for seeing, hearing, or inferring episodes respectively). Experiment 5 found that children had some success in recognizing and remembering other people’s sources of knowledge (seeing, hearing or inferring; 70% of correct responses overall). Finally, Experiment 6 demonstrated that children can assess the reliability of different sources (specifically seeing vs. hearing) and trust one source more than another when tested non-linguistically (65.85% of correct responses). Taken together, our results support the conclusion that the acquisition of evidential morphology poses considerable problems for learners; however, despite previous suggestions, these problems are not conceptual in nature. We hypothesize instead that the unavailability of stable and obvious situational correlates when an evidential morpheme is produced complicates the process of mapping morphemes onto evidential categories (cf. Gleitman, 1990), even when such categories are conceptually available to the child.